This invention relates generally to an apparatus for conveying railroad tie plates placed thereon from the bed of a railroad track mounted highway truck or railroad car to the bed of a railroad track in a predetermined and spaced apart sequence as the apparatus and the truck or car move in unison along the track.
Machines which apply or drive tie plates to or on railroad ties have long been known in the prior art. See, for example, U.S. Pat. No. 567,232 granted to W. H. Greenshield on Sep. 8, 1896, U.S. Pat. No. 594,731 granted to G. W. Dowe on Nov. 30, 1897 and U.S. Pat. No. 636,702 granted to G. R. Wilton on Nov. 7, 1899. These and other such patents relate to machines which affix or secure tie plates to railroad ties.
But there has been a long felt need in the railroad art for an apparatus which can deposit tie plates, one at a time, on and along the bed of a railroad track at convenient spaced apart positions so that, later, as old railroad rails and tie plates are removed, the previously deposited new tie plates can be readily handled and substituted in place of the old tie plates, preparatory to laying new rails. Since each railroad tie requires a pair of such tie plates, one under each rail, it would be convenient to deposit one of such pair of replacement tie plates on a tie, centered between the rails, and the other, so as to be approximately centered between that tie and the next succeeding tie and also centered between the rails. According to the present custom, ties are located on successive longitudinal centerlines which are about 22 inches apart on a straight course of track in the United States. Thus, it would be desirable to provide an apparatus for depositing such replacement plates about eleven inches apart along the centerline of a railroad track. This will readily permit a worker to reach any two successively deposited tie plates for replacement of the two old tie plates on a nearest one of the railroad ties, preparatory to replacing the rails thereon.
By means of my invention, this particular long felt need in the prior art can now be met.
It is an object of my invention to provide an apparatus and method for conveying railroad tie plates from storage on a railroad track mounted carrier to the bed of a railroad track in a predetermined, spaced apart sequence as the apparatus and carrier move in unison along the track.
Briefly, in accordance with this object, a method for depositing tie plates in a spaced apart sequence along a bed of a railroad track from a mobile tie plate carrier mounted on the track is provided. The steps of the method include providing a gravity feed roller conveyor, an upper end portion of which is mounted in a tie plate receiving position on the carrier. A lower tie plate discharging end portion of the roller conveyor is attached to support structure carried by a pair of railroad wheels mounted on the track for movement with the carrier. The method further includes loading the plates, one after another, on the upper end portion of the roller conveyor such that the tie plates gravitate toward the lower end portion. The method also includes capturing each of the tie plates separately and in sequence as it gravitates down the roller conveyor to a preselected position on the roller conveyor near a discharge end of the lower end portion. The method additionally includes releasing each of the tie plates, following the step of capturing it, at a predetermined rate which depends on the distance traveled along the track by the pair of wheels since release of an immesiately preceding one of the tie plates such that successive ones of the tie plates can gravitate off of the discharge end onto the track bed at predetermined spaced apart positions as the carrier and conveyor move along the track.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and attached drawings which, by way of example, only a preferred embodiment of my invention is explained and illustrated.